Thermostat or heat-regulator for incubators.



C. P. McANDREW.

IHERMOSTAT 0R HEAT REGULATOR FOR INCUBATORS,

APPLICATION FILED sumzs, 916.

1,235,348. Patented July 31, 1917,

,4 TTOHNEYS UNITED STATES PATENT OFFICE.

CHARLES P. MCANDREW, OF ELLSWORTH, WISCONSIN.

I .HERIVIOSTA'L OR HEAT-REGULATOR FOR INCUBATORS.

Application filed September 26, 1916.

To all whom it may concern:

Be it known that I, CHARLES P. MoAN- DREW, a citizen of the United States, and a resident of the village of Ellsworth, in the county of Pierce and State of Wisconsin, have invented a new and Improved Thermostat or HeatR-egulator for Incubators, of which the following is a full, clear, and exact description.

This invention relates to thermostats of the bi-metallic bar type, and the invention has for its general objects to improve the construction and operation of devices of this character so as to be reliable and efficient in use, comparatively simple and inexpensive to manufacture, and so designed as to be extremely sensitive, so that when applied to an incubator or the like, the tem perature can be maintained substantially constant within very narrow limits.

With such objects in view, and others which will appear as the description proceeds, the invention comprises various novel features of construction and arrangement of parts which will be set forth with particularity in the following description and claims appended hereto.

In the accompanying drawing, which illustrates one embodiment of the invention and wherein similar characters of reference indicate corresponding parts in all the views,

Figure l is a fragmentary sectional view of an incubator with the thermostat applied thereto;

Fig. 2 is an enlarged longitudinal section of the thermostat;

Fig. 3 is a side view; and

Fig. 4 is a transverse section on the line 4-4,.Fig. 2-.

Referring to the drawing, A designates the casing of an incubator which is heated by a heater B having a connection 1 with the incubator casing, and in the latter is the thermostat C which is connected by a rod 2 with the lever 3 at the top of the incubator, which lever controls the damper of the heater and thereby regulates t e amounttof hot air passing to the incubator.

The-thermostat is made up of a plurality of long strips of iron or steel 8 and long strips of zinc 2, in combination with the short strips of zinc 2. These strips are preferably, although not necessarily, made channel-shaped and are nested together, as clearly shown in Fig. 41 All of the long Specification of Letters Patent.

Patented July 31, 1917.

Serial No. 122,218.

strips are secured together by a rivet at at one end and this rivet also secures to the thermostat a bracket 5, whereby the thermostat can be secured at one end to a support. The steel strips are three in number in the present instance, one being disposed at the center and two at the top and bottom, and the long strips of zinc are disposed at opposite sides of the middle strip of steel, and these three strips are secured together at their free ends by a rivet 6 or equivalent means. The short strips of zinc are secured by rivets 7 and 8, respectively. with the free ends of the upper and lower strips of steel, and the opposite ends of the short strips 2 are riveted to the long strips of zinc at 9 and 10 adjacent the centers of the said long strips of zinc. The upper strip of steel has riveted thereto a bracket 11 whereby the opposite end of the thermostat can be fastened to a support, such as the wall of the incubator casing. An apertured lug 12 is fastened to the free end of the lower steel strip and it is to this lug that the rod 2 is connected. The zinc and steel having different coefiicients of expansion and the strips being arranged. in the manner set forth cause a wide range of movement be tween the anchored end of the upper steel strip and the free end of the lower steel strip, so that the heat regulator of the incubator will be extremely sensitive to temperature variations, and consequently the hot air supplied to the incubator will be regulated to a nicety. The number of strips can be varied as required, according to the range of movement desired for given temperatures.

From the foregoing description taken in connection with the accompanying drawing, the advantages of the construction and method of operation will be readily understood by those skilled in the art to which the invention appertains, and while I have described the principle of operation, to gether with the device which I now consider to be the best embodiment thereof, I desire to have it understood that the device shown is merely illustrative and that such changes may be made when desired as fall within the scope of the appended claims.

Having thus described my invention, I claim as new and desire to secure by Letters Patent:

1. A thermostat comprising outer bars and an intermediate bar. of similar mate rial, bars at opposite sides of the intermediate bar and of different material, all of said liars being fastened together at one end and the opposite ends being relati ely movable, and short bars connected with the free ends of the outer bars and with the intermediate portions of the bars fastened to the intermediate bar.

2. A thermostat comprising, outer bars and an intermediate bar of similar material, bars at opposite sides of the intermediate bar and of different material, all of said bars being fastened together at one end and the opposite ends being, relatively movable, and short bars connected With the free ends of the outer bars and with the intermediate portions of the bars fastened to the intermediate bar, the bars to one side of the intermediate bar being charmeled and nested together, and the bars at the opposite side being channeled and oppositelv disposed and nested togetheix 3. A thermostat comprising a central barlike section made up of a central strip and side strips fastened together at their ends, outer bar-like sections, means for fastening at one end all the sections together with the other ends free, a strip fastened to the free end of one outer section and fastened to an intermediate portion of the adjacent outer strip of the central section, and a strip fastened to the free end of the other outer section and to an intermediate portion of, the adjacent outer strip of the central section.

CHARLES P. MCANDREW.

Copies of this patent may be obtained for f ve cents each, by addressing the Commissioner of Patents. Washington, D. 0. 

